Paxson will wear jersey No. 71 for the Steelers.
The Steelers made room on their roster for Paxson by releasing veteran running back Najeh Davenport, who most recently signed with the team on Nov. 27. Davenport had seen action in four games this year with the Steelers, but was not active for Pittsburgh's Week 13 game at New England.
The Steelers also announced that rookie cornerback Roy Lewis has been re-signed to their practice squad. Lewis has played in one game for the Steelers this season, versus San Diego, after spending most of the year on the team's practice squad.